The N52B25 engine is a reliable and technologically advanced inline six-cylinder engine developed by BMW. Its production was carried out from 2005 to 2011. The main advantages of this engine are high power, economy and durability. Below is a table with detailed characteristics.
Characteristics of the N52B25 engine
| Characteristic | Value |
|---|---|
| Manufacturing | Munich Plant |
| Engine make | N52 |
| Years of production | 2005-2011 |
| Cylinder block material | Magnesium-aluminum |
| Power system | Injector |
| Engine type | Ready |
| Number of cylinders | 6 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 78.8 |
| Cylinder diameter, mm | 82 |
| Compression ratio | 11 |
| Engine displacement, cc | 2497 |
| Engine power, hp/rpm | 177/5800 204/6400 218/6500 |
| Torque, Nm/rpm | 230/3500-5000 250/2750-3000 250/2750-4250 |
| Environmental standards | Euro 5 |
| Engine weight, kg | ~120 |
| Oil consumption, gr./1000 km | To 1000 |
| Oil volume in the engine, l | 6.5 (approximately 6.0 liters when changing) |
Application of the N52B25 engine
This engine was fitted to a wide range of BMW models such as:
- BMW 323i (E90)
- BMW 325i (E90)
- BMW 523i (E60)
- BMW 525i (E60)
- BMW 523i (F10)
- BMW X3 (E83)
- BMW Z4 (E85)
- BMW Z4 (E89)
Engine Features
- Magnesium-aluminum cylinder block: makes the engine lightweight (~120 kg) while maintaining strength.
- Double VANOS system: provides smooth timing control, which improves power and economy.
- Environmental standards: Euro 5 compliant.
Reliability and repair of the BMW N52B25 engine
Another 2.5-liter engine of a new series N52 (which included N52B30), with an in-line layout and six cylinders. The N52B25 appeared in 2005 as a replacement for the popular M54B25 and unlike past evolutions of the M-family, it is now a completely new engine. At the heart of the N52 is an even lighter magnesium-aluminum cylinder block, with a new lightweight ball joint and modified crankshaft.
The N52B25 features an updated cylinder head with the familiar Double-VANOS system, or simply put, Double-VANOS. In addition, the Valvetronic valve lift system has been added to the Vanos, which increases output and fuel efficiency. A chain is used in the timing drive, DISA variable length manifold is used on the intake, injectors are installed in the cylinder head, Siemens MSV70 engine management system.
This motor was used on BMW cars with index 23i and 25i.
The replacement for the N52B25 engine came out already in 2 years after its beginning of production, in the person of N53B25 and strangled versions of N53B30, but 2.5 liters. N52 was produced for quite some time and was removed from production only in 2011.
Modifications of the BMW N52B25 engine
- N52B25U1 (2005 – 2008) – the basic engine is strangled with an intake manifold, power 177 hp at 5800 rpm, torque 230 Nm at 3500-5000 rpm. For versions with index 23i.
- N52B25 (2009 – 2011) – blown engine with a different intake manifold, rated at 204 hp at 6400 rpm, torque 250 Nm at 2750 rpm. For versions with index 23i.
- N52B25O1 (2005 – 2009 model years) is the most popular version at 218 hp at 6500 rpm, 250 Nm of torque at 2750-4250 rpm. For versions with the index 25i.
Problems and disadvantages of BMW N52B25 engines
- The most important problem of the N52B25 is oil burn. The matter is all in thin oil rings, which are quickly encrusted, as well as in dead oil caps. And on N52 such things can happen on mileage up to 100 thousand kilometers… Check the condition, buy new caps and rings. It is not superfluous to check the condition of the crankcase gas ventilation valve (CVCG).
The problem has been solved on motors since 2007, named N52NB25 (black cap). - If you spit on the high oil consumption and continue to drive as it is, then a little later begin to clog catalytic converters. Exit: A. Buy new catalytic converters, it is expensive. B. Buy flame arrestors, it’s cheap.
- Ticking sound. It appears on cold and is a peculiarity of engines produced before 2009. There are no negative consequences for the motor from this.
- Swimming revs. Such problems are associated, as a rule, with Valvetronic, flow meter or Vanos valves. On N52 vanos quite often causes problems due to improper maintenance (oil change once every 20 thousand kilometers, use of low-quality oil). Vanos repair is simple: first flush the vanos valves, if the problem persists, then replace. Check.
In addition, the engine is very prone to overheating, you need to constantly monitor the cooling system, radiator cleanliness, the H52 has a not too durable electronic pump, requiring replacement every ~80-100 thousand km, To reduce the likelihood of various troubles, oil in the engine N52 is recommended to pour high quality, recommended by the manufacturer, the gasoline is also not worth saving.
Should I buy a BMW with such an engine? Undesirable, it is better to buy a reliable M54 or N52B30 engine.
Tuning BMW N52B25 engine
Chip tuning
This motor is very unsuitable for tuning and modification, so it will be optimal to buy a BMW with more help. If you really want to play in tuning, then the easiest method to increase power on N52B25 will be chip tuning. Buying a sport exhaust system and air filter, as well as a wicked firmware will allow you to raise the power by ~20 hp.
BMW owners with 23i index should buy an intake manifold from N52B25O1 (25i index). This step will increase the maximum power a little more (about 15-20 hp).
N52B25 Compressor
For those who will find the above described measures not enough, it is necessary to prepare money for supercharger. Buying a compressor kit from ARMA will increase the power on the stock piston almost to 300 hp. However, it is cheaper to buy a BMW with N54/N55, index 35i.
MOTOR RATING: 4